Is the angle that the Bonneville pipes leave the head actually different? They use the same head, so I don't see why you couldn't use them unless they come out forward more instead of off to the sides, but the Bonnies have two down tubes also so I think they should fit just fine.
They look to come out at the same angle as our headers do, plus with that same ugly oil cooler, it looks like the down tubes are the same distance apart.
